System for delivering solid particulate matter for loading

ABSTRACT

An assembly for transferring solid particulate matter has a pressurized vessel for retaining a pre-determined quantity of the solid material. A transfer conduit connected to the vessel carries the solid material to a loading vessel, be it a processing tank, a storage vessel, or any other similar container. A discharge nozzle carried by a distant end of the transfer conduit is connected to a vacuum source, whereby a slight vacuum is created at the discharge opening. A separate dust removal conduit is secured immediately adjacent to the discharge nozzle for removal of the dust particles away from the discharge nozzle. The dust particles are collected in a separate vessel, which is mounted in a flow of air from the dust collection conduit and an exhaust fan. Mesh sleeves suspended in the vessel, capturing the dust particles on exterior surface thereof. Periodically, the dust particles are dislodged from the sleeves by blowing air through the sleeves. The dislodged dust particles are collected for disposal or recycling.

BACKGROUND OF THE INVENTION

This invention relates to an assembly for transferring solid particulatematter, with the assistance of pressurized airflow into a loadingcontainer, which may be a storage container, a processing tank, or othersimilar vessel. Even more particularly, the present invention relates toan assembly for transferring solid pelletized material, such as forinstance a catalyst substance, into a loading container, wherein thepelletized material generates dust during the transfer process.

Many industries require transport, or delivery of solid particles fromstorage area or delivery container into another storage container or aprocessing tank. One of such industries is a chemical industry wherepre-determined quantities of solid pellets are loaded into a processingvessel or converter. For instance, sulfuric acid manufacturing plantsuse a vanadium catalyst, which is supplied in a pelletized form in bagsor drums. The catalyst pebbles then need to be loaded into the converteror container where a chemical reaction for generation of gases takesplace.

Conventionally, acid processing tanks are upright vessels with a closedtop. A plurality of levels or beds of catalyst is contained in eachconverter vessel. The loading takes place through the top of theconverter in the first bed of catalyst and through opening in thesidewall of the converter in lower beds. During the loading operation,the catalyst pellets, being delivered by gravity, generate a significantamount of dust. The personnel who perform the loading operation, bynecessity have to wear facemasks, respirators, and similar protectivegear to avoid breathing in the dust that heavily permeates the areawhere the loading takes place.

Similar conditions exist in loading operations of other solid particles,for instance, during grain loading into silos and other storagefacilities. The loading space has to be equipped with adequateventilation to minimize the dust particles retention in the loading areaand creation of health hazards in such areas.

A useful assembly for handling solid particulate matter is disclosed inU.S. Pat. No. 7,635,011, which teaches the use of a pressurized vesselfor retaining a pre-determined quantity of the solid material. Atransfer conduit connected to the vessel carries the solid material to aloading vessel, be it a processing tank, a storage vessel, or any othersimilar container. A discharge nozzle carried by a distant end of thetransfer conduit has a plurality of perforations that allow removal ofthe dust particles by suction from the discharge nozzle. A separate dustremoval conduit is secured immediately adjacent to the discharge nozzlefor removal of the dust particles away from the discharge nozzle. Thenozzle is also connected to a dust collection container. Avacuum-assisted suction force is created in the dust collectioncontainer to facilitate entrapment of dust particles generated duringtransfer of the solid material through the discharge container andcarrying of the dust particles away from the discharge opening of thedischarge nozzle into the dust collection container. While the assemblyaccording to the '011 patent works satisfactory in many circumstances,there was observed a need for a better control of the transfer processfor moving the solid particulate matter through the transfer conduit.Additionally, it was discovered that there may be a more enhanced dustentrapment device that may be used in the system.

The present invention contemplates elimination of drawbacks associatedwith the prior design and provision of an improved loading system thatimproves the control over the transfer process for solid particulatematter while improving dust-collection capabilities.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide animproved loading system for transferring solid pelletized items from astorage facility to a loading container, while avoiding spreading ofdust in the loading area.

It is another object of the present invention to provide an improvedloading system for moving solid pelletized items with the help ofregulated air pressure from a storage container to a processing tank.

It is a further object of the present invention to provide an assemblyfor loading pellets of sulfuric acid catalyst, while removing dustgenerated by the friction of pellets before the dust escapes the loadingand transfer conduits.

It is also an object of the present invention to provide a system fordelivering solid particulate matter, wherein the dust particles arecollected in detachable sleeves mounted in the dust collection vessel.

These and other objects of the present invention are achieved through aprovision of a system for delivering solid particulate matter, forinstance catalyst pellets for loading. The system comprises apressurized vessel or container configured for retaining apre-determined quantity of the solid particulate matter. A source ofpressurized gas retains a pre-determined pressure inside the pressurizedvessel to facilitate movement of the particulate matter through thecontainer and into a transfer conduit. The pressure inside the containercan be manually or automatically controlled using a control panel. Thepressure created in the container facilitates movement of theparticulate matter through the transfer conduit to a distant endthereof, where a discharge nozzle is mounted.

As the particulate matter moves through the transfer conduit the pelletsstrike against each other and create dust particles, which must beremoved prior to loading of the pellets for processing in a catalyticconverter or other tank outside of the system. A balancing vacuum sourcecreates a slight vacuum at the discharge nozzle assembly for removal ofthe dust particles from the transfer conduit. The removed dust particlesare pulled into a dust collection vessel, where they settle on meshsleeves suspended in the dust collection vessel in the path of flow fromthe dust collection conduit and an exhaust pump or fan.

Since the dust particles often times contain valuable recyclablematerial, the dust particles are collected from the mesh sleeves byblowing air through the sleeves using an auxiliary surge tank. Thedislodged dust particles fall under gravity into the bottom of the dustcollection vessel and are removed therefrom into a container positionedbelow the dust collection vessel.

The balance between pressurized container and the vacuum pull of thedust particles is maintained to facilitate efficient, dust-free deliveryof the palletized material to the desired processing tank.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the drawings, wherein like parts aredesignated by like numerals, and wherein

FIG. 1 is a schematic view of the loading system in accordance with thepresent invention using manual controls for admitting air into thepressurized container.

FIG. 2 is a cross sectional view of the dust collection vessel takenalong lines 2-2 of FIG. 1.

FIG. 3 is a detail view of the dust collection sleeves positioned in thedust collection vessel.

FIG. 4 is a detail view of a trap door at a discharge end of thedischarge nozzle.

FIG. 5 is a schematic view of the loading system in accordance with thepresent invention using automatic controls for admitting air into thepressurized container.

FIG. 6 is a cross sectional view of the dust collection vessel takenalong lines 6-6 of FIG. 5.

FIG. 7 is a detail view of the dust collection sleeves positioned in thedust collection vessel of the embodiment of FIG. 5.

FIG. 8 is a detail view of a trap door at a discharge end of thedischarge nozzle of the embodiment of FIG. 5.

FIG. 9 is a plan view illustrating movement of the regulating door inconjunction with the discharge nozzle of the transfer conduit.

DETAILED DESCRIPTION OF THE INVENTION

Turning now to the drawings in more detail, the system of the presentinvention is designated by numeral 10 in FIG. 11. As can be seen in thedrawing, the system 10 comprises a pressurized upright container 12having a bottom discharge 14 in fluid communication with a transferconduit 16. The transfer conduit 16 is provided with a discharge nozzleassembly 20 at the distant end thereof. A dust removal conduit 22 is influid communication with the discharge nozzle assembly 20. The dustconduit 22 is connected to the discharge nozzle assembly 20 upstreamfrom a discharge opening 98 of the discharge nozzle assembly 20. Thedust removal conduit 22 is operationally connected to a dust collectioncontainer, or vessel 26 and is in fluid communication therewith. Achamber 28 is formed in the dust collection vessel 26.

The pressurized container 12 is provided with a top lid 30 that allowsloading of the container 12 from the top. The items to be transferred,for instance pellets 38 of the catalyst, are loaded by gravity into theupright container 12. A conduit 32 fluidly connects the container 12with a source of compressed (pressurized) air supply (not shown). Aregulating valve 33 is mounted in the conduit 32 for regulating deliveryof the pressurized air into the container 12. A pressure indicator 35 isoperationally connected to the container 12; the pressure indicator 35is configured to detect pressure inside the container 12 during theloading operation. The container 12 is vertically oriented to facilitatemovement of the solid particulate matter loaded into the container 12from the top 34 to the bottom 36 thereof.

The bottom 36 of the container 12, if desired, can be formed as aninverted cone to facilitate movement of the pelletized solid material inthe interior of the container 12 toward to apex of the cone, whichserves as a discharge outlet of the container 12. As can be seen in FIG.1, the solid particles occupy the lower portion of the container 12 withthe top portion 34 being filled with pressurized air to push the pelletsdownwardly and into the discharge 14 and then into the transfer conduit16. A gate valve 40 is positioned at the interface of the dischargeopening 14 and the transfer conduit 16 to regulate movement of solidparticles from the container 12 downstream into the transfer conduit 16.The gate valve 40 moves between an open position and a closed positionin response to a control signal from a control valve 42 mounted inoperational relationship to the air supply conduit 32 and the regulatingvalve 33.

The container 12 is schematically shown as resting on a plurality ofsupporting legs 43 to allow the bottom 36 of the container 12 to beelevated above the conduit 16. The height of the supporting legs 43differs depending on the types of container design used.

The solid pellets 38 move through the bottom discharge 14 into theconduit 16 in the direction away from the container 12. The air pressureat the loading side 15 of the container 12 is approximately 375 CFMpushing the pellets 38 into the container 12. The pressure inside thecontainer 12, maintained by the compressed air supply as detected by thepressure indicator 35 is maintained at a level of between 5 p.s.i. and15 p.s.i. In one of the preferred embodiments, that pressure is about 8p.s.i. to start the movement of the pellets 38 from the container 12into the transfer conduit 16. The pressure at the discharge 14 ismaintained at a sufficient level to allow movement of the pellets 38through the transfer conduit 16 towards the discharge nozzle assembly20. While the pressure in the transfer conduit 16 and the vessel 12 willnecessarily differ depending on the material being transferred by theassembly 10, one of the embodiments of the present invention fortransferring sulfuric acid catalysts provides for pressurizing of thevessel 5 to 18 p.s.i. The discharge 14 on the bottom of the container 12opens once the pre-determined pressure is reached. In one aspect of theinvention, a compressor generating up to 400 cubic feet per minute (CFM)is used.

To facilitate capturing of the dust particles and movement of the dustparticles into the dust collection vessel 26, the system 10 provides forthe use of a vacuum exhaust pump 50 connected to the interior of thedust collection vessel 26. A source of vacuum (not shown) can be avacuum truck, which is delivered to the site and connected to the vacuumpump 50 by a vacuum delivery conduit 52. A vacuum control valve 54 ismounted in the vacuum delivery conduit 52. An exhaust conduit 56 isconnected to the top of the dust collection vessel 26. An exhaust valve58 is mounted downstream of the exhaust pump 50 in the exhaust conduit56.

As the pelletized items 38 move through the vessel 12 into the conduit16, they necessarily strike against each other; the friction causessmall particles to be chipped off from the pellets 38, generating dustthat also travels through the container 12 and the transfer conduit 16.The tiny solid particles then travel along the transfer conduit 16 andreach the discharge nozzle assembly 20. A slight vacuum of approximately0 to 5 p.s.i., at the discharge nozzle assembly 20 creates a largeexpansion of gas to about 3500 CFM. That air travels over the materialbeing transferred through the discharge nozzle assembly 20 such that thedust particles are captured by the vacuum and pulled into the dustremoval conduit 22 and then into the dust collection vessel 26.

Sometimes, an operator loading the palletized material 38 into acontainer, for instance an oil processing vessel (not shown), detectsthat the pellets 38 exit the discharge nozzle 20 at a greater speed thannecessary and that dust content gas increased. Such observation allowsthe operator to determine that the speed of travel of the palletizedmaterial through the transfer conduit 16 is too great. To betterregulate the speed of pellets discharge, the system of the presentinvention provides for the use of a regulating door 60, which movesbetween a closed and a plurality of partially open positions.

The regulating door 60 is mounted in the discharge nozzle assembly 20pivoting about a pivot point 62 in the direction of arrow 63. Theregulating door 60 can be rectangular in shape, as shown in FIGS. 4 and8. A knob 64 is secured to an exterior surface 61 of the door 60 toallow the operator to manually pull open the door 60 and thus reduce thevacuum strength pulling the pellets through the discharge conduit 16.The door 60 can be moved into a fully open position or a plurality ofpartially open positions, giving the operator control over the speed ofthe pellet discharge at the exit point 98.

As can be seen in FIG. 9, the discharge opening 98 is formed in adischarge nozzle plate 100. The discharge nozzle plate 100 surrounds thedischarge opening 98, through which the pellets 38 exit the system 10.The regulating door 60 is formed with an indentation 102 on an innercontact surface 63 thereof. A plurality of spaced-apart raised members104 is provided on the contact surface of the discharge nozzle plate100. As any of the raised members 104 is aligned with the indentation102 an matingly engages therewith, the door 60 opens in the selectedposition, allowing the discharge opening 98 to be fully closed,partially open or fully open, as the operator chooses.

The dust collection conduit 22 is fluidly connected to an inlet opening27 formed in the dust collection vessel 26. A plurality of dustcollection members 70 is suspended in the dust collection vessel 26above a dust inlet opening above the inlet opening 27. The dustcollection members 70 are suspended in the dust collection vessel 26 inthe path of suction flow between the dust collection conduit 22 and theexhaust pump or fan 50.

Each of the dust collection members 70 comprises a frame 72, which canbe formed by a thin rod bent into a generally U-shaped configuration. Amesh dust sleeve 74 is stretched over the frame 72 and is detachablysecured on top by a clamp or rubber band 76. The mesh sleeve 74 isformed from a porous flexible material with small openings 75 that allowair circulation through the dust sleeve while trapping dust particles onthe exterior of the sleeve 74. As the vacuum created by the vacuumsource pulls across the interior of the chamber 28 of the dustcollection vessel 26, the dust particles settle on the outside of thedust sleeves 74, while the dust-free air exhausts through the exhaustconduit 56. It should be noted that the dust particles may containvaluable materials, for instance silver (Ag), that is used in somecatalysts.

The system of the present invention comprises a means for dislodging andcapturing or collecting the dust particles for recycling or disposal. Ascan be seen in FIGS. 1 and 5, a surge tank 80 is operationally connectedto a surge conduit 82 mounted across the interior of the chamber 28. Thesurge tank 80 is connected to a compressed air supply (not shown)through a supply valve 84 and to a control panel 200 of the system 10through a surge control valve 86.

The surge conduit 82 has channels connecting the surge conduit 82 to thedust collection members 70. As the dust collects on the exterior of thesleeves 74 and the flow of exhaust air through the exhaust conduit 56decreases, the system operator can detect that the sleeves 74 havecollected dust that impedes the air flow through the sleeves.Periodically, the operator can close off the valve into the transferconduit 16 and switch off the exhaust pump 50. The vacuum valve 54 isclosed, thus isolating the dust collection vessel from the remainder ofthe system. If desired, the closing of the valves and vacuum supply canbe performed automatically upon detection of certain pressure across theexhaust conduit 56 using the control panel 200.

The operator then opens the supply of compressed air through the surgetank 80, blowing the compressed air across the interior of the sleeves74. The dust particles, which have settled on the sleeves 74 aredislodged from the sleeves 74 and fall under gravity into the bottom 29of the dust collection vessel 26. The dust particles 87 collect in theconical bottom 29 of the vessel 26. The operator can open the bottomdoor 88 in the bottom portion 29 of the vessel 26 and allow the dustparticles 87 to drop into a barrel 89 positioned under the door 88. Thecollected dust particles containing valuable metals and other materialscan be sent to recycling and manufacturing of the catalyst pellets ordisposed in a safe manner.

The embodiment of the present invention, system 120, shown in FIGS. 5-8,is rather similar to the embodiment shown in FIGS. 1-5 and 9, except inthe system 120, the delivery of compressed air supply into the inletside of the transfer conduit 16 and into the pellet container 12 isperformed automatically without human intervention using the controlpanel 200. In both embodiments, substantially all dust particles, or asignificant amount thereof is diverted from reaching the dischargeopening 98 and escaping into the atmosphere. During a catalyst loadingoperation, the discharge nozzle end 98 is placed in the converter andthe catalyst is distributed as required.

The loading assembly of the present invention allows scrubbing of thecatalysts or other pelletized solid particles and remove dust from theloading conduits before they escape into the surrounding area or reachthe processing vessels, catalytic converters, storage containers, andthe like. A careful balance must be observed between the amount ofpressure created in the vessel 12 and the dust removal conduit 22.Similarly, if the discharge nozzle 20 is selected for high-speeddischarge, the dust particles may not have a chance to be directed intothe flow moving towards the conduit 22.

The system 10 and the system 120 allow control of the catalyst beingloaded into the container 12 as well as control of the vacuum pull byincreasing the revolutions of the exhaust fan or pump 50 so as to createsufficient amount of low pressure at the precise point in the dischargeassembly. The dust particles separated from the solid pellets arediverted from the discharge outlet into the dust collection conduit 22and dust collection vessel 26, thereby allowing the dust particles to becollected, containerized and recycled.

These major control points allow balancing of the loading process andcreate a virtually dust-free delivery of the catalyst for a chemicalreaction outside of the system of the present invention. As thepalletized material moves at the selected speed through the transferconduit, the dust particles are allowed to separate from the palletizedmaterial and then redirected from the discharge opening 98 to the dustcollector. The timing and speed of travel of the pellets through thesystems 10 or 120 allow obtaining maximum separation of the dustparticles depending on the size and type of the palletized material.

It should be noted that the vacuum source should not overpower thepositive air compressor delivering compressed air through the supplyline 32. The pressure in the container 12 is detected and controlledusing the pressure indicator 35 so as not to overcome the vacuum forcerequired for proper particle separation. In one aspect of the invention,the inlet pressure of about 5 p.s.i. at the delivery of the pellets intothe container 12 and control of the exhaust vacuum fan 50 allows tocreate the necessary equilibrium for maximum collection of the dustparticles without sacrificing the delivery of the palletized materialfor loading. In one aspect, the dust collection vessel 26 may have acapacity of moving 3,000 cubic feet per minute of the airflow. Ofcourse, the vacuum generated in the conduit 22 and the pressure valuesin the container 12 can be different for different types of solidparticulate matter.

Many changes and modifications can be made in the apparatus of thepresent invention without departing from the spirit thereof. I,therefore, pray that my rights to the present invention be limited onlyby the scope of the appended claims.

1. A system for delivering solid particulate matter for loading,comprising: a pressurized vessel configured for retaining apre-determined quantity of the solid particulate matter, saidpressurized vessel being fluidly connected to a supply of pressurizedgas; a means for controlling delivery of pressurized gas into thepressurized vessel operationally connected to the pressurized vessel; atransfer conduit configured for transferring the solid particulatematter from the pressurized vessel for loading, said transfer conduitcarrying a discharge nozzle assembly with a discharge opening on adistant end thereof, said discharge nozzle assembly having a regulatingdoor configured for moving between a closed position and a plurality ofselected open positions and for regulating speed of delivery of theparticulate matter through the discharge opening; a means mountedupstream from said discharge opening for removing dust particles fromsaid discharge nozzle assembly, said dust removing means being in fluidcommunication with a vacuum source, said means for removing dustparticles being configured to create suction force sufficient to divertthe dust particles from the discharge opening; and a control paneloperationally connected to the pressurized vessel and the means forremoving the dust particles.
 2. The system of claim 1, wherein saidmeans for removing dust particles comprises a dust collection vesseloperationally connected to an exhaust fan and a vacuum source, and adust collection conduit mounted in fluid communication between the dustcollection vessel and the discharge nozzle assembly.
 3. The system ofclaim 3, wherein said dust collection vessel comprises an interiorchamber, and said means for removing dust particles further comprises aplurality of porous dust collection members suspended within theinterior chamber.
 4. The system of claim 3, wherein each of the dustcollection members is configured to retain the dust particles onexterior surface thereof.
 5. The system of claim 4, wherein each of thedust collection members comprises a mesh sleeve stretched over an openframe.
 6. The system of claim 3, wherein the means for removing the dustparticles further comprises a means for dislodging the dust particlessettled on the dust collection members.
 7. The system of claim 6,wherein the means for dislodging the dust particles settled on the dustcollection members comprises a surge tank fluidly connected to the dustcollection members, said surge tank being configured to deliverpressurized air through the dust collection members.
 8. The system ofclaim 7, wherein the means for removing the dust particles furthercomprises a means for collecting the dislodged dust particles.
 9. Thesystem of claim 8, wherein the means for collecting the dislodged dustparticles comprises a bottom door formed in the dust collection vesseland a container mounted below the bottom door for receiving thedislodged dust particles.
 10. The system of claim 6, wherein the meansfor removing the dust particles further comprises a means for connectingthe means for dislodging dust particles to the control panel.
 11. Thesystem of 1, further comprising a means for detecting pressure withinthe pressurized vessel.
 12. The system of claim 11, wherein the meansfor detecting pressure within the pressurized vessel is manuallyoperated.
 13. The system of claim 11, wherein the means for detectingpressure within the pressurized vessel is configured for automaticcontrol by the control panel.
 14. The system of claim 1, wherein saidpressurized vessel comprises an outlet, said outlet being operationallyconnected to the means for controlling delivery of pressurized gas intothe pressurized vessel.
 15. The system of claim 1, wherein saidregulating door is pivotally mounted in relation to the discharge nozzleassembly.
 16. The system of claim 1, wherein the regulating doorcomprises a contact surface, and wherein an indentation is formed insaid contact surface.
 17. The system of claim 16, where the dischargenozzle assembly comprises a contact plate configured for a sealingcontact with the regulating door, and wherein a plurality ofspaced-apart raised members is formed on said contact plate, each of theraised members being configured for mating engagement with theindentation in the contact surface of the regulating door.
 18. Thesystem of claim 17, wherein each of the raised members is configured formating engagement with the indentation in the contact surface of theregulating door.
 19. A system for delivering solid particulate matterfor loading, comprising: a pressurized vessel configured for retaining apre-determined quantity of the solid particulate matter, saidpressurized vessel being fluidly connected to a supply of pressurizedgas; a means for controlling delivery of pressurized gas into thepressurized vessel operationally connected to the pressurized vessel; atransfer conduit configured for transferring the solid particulatematter from the pressurized vessel for loading, said transfer conduitcarrying a discharge nozzle assembly with a discharge opening on adistant end thereof; a means mounted upstream from said dischargeopening for removing dust particles from said discharge nozzle assembly,said dust removing means being in fluid communication with a vacuumsource, said means for removing the dust particles being configured tocreate suction force sufficient to divert the dust particles from thedischarge nozzle assembly; a means for collecting the dust particlesremoved from the discharge nozzle assembly; and a control paneloperationally connected to the pressurized vessel and the means forremoving the dust particles.
 20. The system of claim 19, wherein saidmeans for collecting the dust particles comprises a dust collectionvessel operationally connected to an exhaust fan and a vacuum source,and a dust collection conduit mounted in fluid communication between thedust collection vessel and the discharge nozzle assembly.
 21. The systemof claim 19, wherein the means for collecting the dust particles furthercomprises a plurality of porous dust collection members suspended withinthe dust collection vessel in a flow path between the dust collectionconduit and the exhaust fan.
 22. The system of claim 21, wherein each ofthe dust collection members is configured to retain the dust particleson exterior surface thereof.
 23. The system of claim 21, wherein each ofthe dust collection members comprises a mesh sleeve stretched over anopen frame.
 24. The system of claim 21, wherein the means for collectingthe dust particles further comprises a means for dislodging the dustparticles settled on the dust collection members.
 25. The system ofclaim 24, wherein the means for dislodging the dust particles comprisesa surge tank fluidly connected to the dust collection members, saidsurge tank being configured to deliver pressurized air through the dustcollection members.
 26. The system of claim 25, wherein the means forcollecting the dust particles further comprises a means for collectingthe dislodged dust particles.
 27. The system of claim 26, wherein themeans for collecting the dislodged dust particles comprises a bottomdoor formed in the dust collection vessel and a container mounted belowthe bottom door for receiving the dislodged dust particles.
 28. Thesystem of claim 19, further comprising a means for detecting pressurewithin the pressurized vessel.
 29. The system of claim 28, wherein themeans for detecting pressure within the pressurized vessel is manuallyoperated.
 30. The system of claim 28, wherein the means for detectingpressure within the pressurized vessel is configured for automaticcontrol by the control panel.
 31. The system of claim 19, wherein saidpressurized vessel comprises an outlet, said outlet being operationallyconnected to the means for controlling delivery of pressurized gas intothe pressurized vessel.
 32. The system of claim 19, wherein saiddischarge nozzle assembly comprises a regulating door configured forselective regulation of delivery of the solid particulate matter throughthe discharge opening.
 33. The system of claim 32, wherein saidregulating door is pivotally mounted in relation to the dischargeopening.
 34. The system of claim 33, wherein the regulating doorcomprises a contact surface, and wherein an indentation is formed insaid contact surface.
 35. The system of claim 34, where the dischargenozzle assembly comprises a contact plate configured for a sealingcontact with the regulating door, and wherein a plurality ofspaced-apart raised members is formed on said contact plate, each of theraised members being configured for mating engagement with theindentation in the contact surface of the regulating door.